4,490 research outputs found

    High-resolution Spectroscopy of [Ne II] Emission from TW Hya

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    We present high-resolution echelle spectra of [Ne II] 12.81 micron emission from the classical T Tauri star (CTTS) TW Hya obtained with MICHELLE on Gemini North. The line is centered at the stellar radial velocity and has an intrinsic FWHM of 21\pm 4 km/s. The line width is broader than other narrow emission lines typically associated with the disk around TW Hya. If formed in a disk, the line broadening could result from turbulence in a warm disk atmosphere, Keplerian rotation at an average distance of 0.1 AU from the star, or a photoevaporative flow from the optically-thin region of the disk. We place upper limits on the [Ne II] emission flux from the CTTSs DP Tau and BP Tau.Comment: Accepted by ApJ. 18 pages, including 2 figures and 2 table

    Infectious disease outbreaks and increased complexity of care

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    Aim: This study examined the effects of healthcare-associated infectious disease outbreaks on nurses’ work in a large acute care hospital in Ontario, Canada. Background: The incidence of healthcare-associated infections has increased. Previous research focuses on epidemiology, healthcare systems, and the economic burden of outbreaks. Few published studies focus on the impact of outbreaks on nurses’ work in acute care facilities. Introduction: Since the severe acute respiratory syndrome epidemic in 2003, combating infectious diseases has become a key issue. Hospitals have implemented measures related to healthcare-associated infections. However, nurses experience challenges in preventing, controlling, and contending with outbreaks. Methods: A retrospective exploratory case study approach was used. Data were collected over a 4-month period in 2012. The incidence rates of site-specific HAIs were analysed, and individual interviews were held with 23 bedside nurses and five nurse managers. Findings: Five themes emerged from the interviews: comparison of healthcare-associated infections outbreaks; the nature of nurses’ work; impact of outbreaks on patient care; innovation and quality control in clinical practice; and increased and expanded IPAC measures. The incidence rates of methicillin-resistant Staphylococcus aureus, Clostridium difficile and vancomycin-resistant enterococci at the study site decreased, but remained above provincial benchmarks. Nurses experienced workload challenges, time pressures and psychological effects stemming from outbreaks and developed various innovations in response. Patient care was also affected. Conclusion: Nurses’ work has been impacted by healthcare-associated infectious disease outbreaks. Nursing workloads should be quantified to facilitate the development of guidelines for optimum nurse–patient ratio during outbreaks. Implications for Nursing and/or Health Policy: A strong evidence-based policy framework is required to address healthcare-associated infectious disease outbreaks. Infection prevention and control guidelines and procedures should be established provincially and nationally. An interdisciplinary approach is essential for the creation of comprehensive and innovative strategies. Nursing research has increased understanding of the implications of infectious diseases in hospitals. Building on the literature, findings from this study can be used to influence policies on the care of patients who have secondary infections. Nurse-driven protocols are important and can lead to the creation of best practice guidelines that can be implemented across settings

    Gravity vs radiation model: on the importance of scale and heterogeneity in commuting flows

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    We test the recently introduced radiation model against the gravity model for the system composed of England and Wales, both for commuting patterns and for public transportation flows. The analysis is performed both at macroscopic scales, i.e. at the national scale, and at microscopic scales, i.e. at the city level. It is shown that the thermodynamic limit assumption for the original radiation model significantly underestimates the commuting flows for large cities. We then generalize the radiation model, introducing the correct normalisation factor for finite systems. We show that even if the gravity model has a better overall performance the parameter-free radiation model gives competitive results, especially for large scales.Comment: in press Phys. Rev. E, 201

    The infrared behaviour of the static potential in perturbative QCD

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    The definition of the quark-antiquark static potential is given within an effective field theory framework. The leading infrared divergences of the static singlet potential in perturbation theory are explicitly calculated.Comment: 4 pages, 2 postscript figures, uses revtex.st

    Evidence for multiple structural genes for the γ chain of human fetal hemoglobin

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    A sequence with a specific residue at each position was proposed for the γ chain of human fetal hemoglobin by Schroeder et al. (1) after a study in which hemoglobin from a number of individual infants was used. We have now examined in part the fetal hemoglobin components of 17 additional infants and have observed that position 136 of the γ chain may be occupied not only by a glycyl residue, as previously reported, but also by an alanyl residue

    Determinants of the outcome on traumatic brain injury patients at Kenyatta National Hospital

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    Introduction: Traumatic brain injury (TBI) is among the leading causes of admissions in hospitals globally. TBI has been attributed with significant morbidity, mortality and disability. Most injuries have mainly been attributed to motor accidents and falls from heights.Traumatic brain injuries represent a significant and growing disease burden in the developing world, and one of the leading causes of death in economically active adults in many low- and middle-income countries.In Kenya, motor vehicle accidents, assaults and motorcycle are significant causes. Per vehicle mile travelled, motorcycle riders have a 34-fold higher risk of death in a crash than people driving vehicles and 8 times more likely to be injured. neurological injury progresses over hours and days, resulting in a secondary injury. Inflammatory and neurotoxic processes result in vasogenic fluid accumulation within the brain, contributing to raised intracranial pressure, hypoperfusion, and cerebral ischaemia a secondary injury may be amenable to intervention. Almost one-third of patients who die after a TBI will talk or obey commands before their death.Physiological insults, Hypoxia, hypotension, hyper - or hypocapnia, hyper - or hypoglycaemia have all been shown to increase the risk of secondary brain injuryObjectives: To determine the patients’ factor, clinical care and systems factor affecting outcome of Traumatic Brain Injury (TBI) patients at Kenyatta National Hospital. Which led to a poor outcome of above 40 years, casual laborers, Polytrauma and time lapse from trauma to hospitalization experienced. The clinical care factors indicating good outcome which included; diagnosis and medication, Nursing care and clinical setting A&E, CCU. Length of hospitalization >10 days. Protocols factors; Patients in surgical wards recording poor outcome.Design: The rationale for using purposive sampling was to be able to distinguish between traumatic brain injury patients, who did not have any neurological problems before the injury, and those who had suffered neurological problems prior to trauma. A descriptive cross-sectional design, Purposive sampling and Quantitative approach to data collection, analysis and presentation was adopted.Setting: The study was carried out at the Accident and Emergency department (A&E), Critical care unit (CCU) and surgical wards of Kenyatta National Hospital (KNH).Subjects: Patients with TBI within 72 hours of injury, aged between 18- 65 years and should have had no previous neurological problem.Results: Patient factors; that led to poor outcome; above 40 years (p=0.042), casual laborers (p=0.043), Polytrauma (p=0.042) and time lapse from trauma to hospitalization (p=0.051). The clinical care factors indicated good outcome which included; diagnosis and medication (p=0.001), Nursing care (p=0.055) and clinical setting A&E (p=0.051), CCU (p=0.032). Length of hospitalization >10 days (p=0.050). Protocols factors; Patients in surgical wards had poor outcome (p=0.051).Conclusion: Patient factor's influenced outcome of TBI, Intensive care and longer time of hospitalization is paramount for better outcome.Recommendation: Setup of a Trauma Neuro Ward and training of Neuro Teams to facilitate professional and quality care to improve outcome of Traumatic Brain Injury patient

    Keck Adaptive Optics Imaging of Nearby Young Stars: Detection of Close Multiple Systems

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    Using adaptive optics on the Keck II 10-meter telescope on Mauna Kea, we have surveyed 24 of the nearest young stars known in search of close companions. Our sample includes members of the MBM 12 and TW Hydrae young associations and the classical T Tauri binary UY Aurigae in the Taurus star-forming region. We present relative photometry and accurate astrometry for 10 close multiple systems. The multiplicity frequency in the TW Hydrae and MBM 12 groups are high in comparison to other young regions, though the significance of this result is low because of the small number statistics. We resolve S 18 into a triple system including a tight 63 mas (projected separation of 17 AU at a distance of 275 pc) binary for the first time, with a hierarchical configuration reminiscent of VW Chamaeleontis and T Tauri. Another tight binary in our sample -- TWA 5Aab (54 mas or 3 AU at 55 pc) -- offers the prospect of dynamical mass measurement using astrometric observations within a few years, and thus could be important for testing pre-main sequence evolutionary models. Our observations confirm with 9-sigma confidence that the brown dwarf TWA 5B is bound to TWA 5A. We find that the flux ratio of UY Aur has changed dramatically, by more than a magnitude in the H-band, possibly as a result of variable extinction. With a smaller flux ratio, the system may once again become detectable as an optical binary, as it was at the time of its discovery in 1944. Taken together, our results demonstrate that adaptive optics on large telescopes is a powerful tool for detecting tight companions, and thus exploring the frequency and configurations of close multiple systems.Comment: accepted for publication in The Astronomical Journa

    A System Dynamics model to predict the impact of COVID-19 in Spain

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    Sanz, MT.; Caselles, A.; Micó, JC.; Soler, C. (2020). A System Dynamics model to predict the impact of COVID-19 in Spain. 146-151. http://hdl.handle.net/10251/178213S14615
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